Update tzlocal to 3.0

[pyup-bot]

This PR updates tzlocal from 1.5.1 to 3.0.

Changelog

3.0

----------------

- Modernized the packaging, moving to setup.cfg etc.

- Handles if the text config files incorrectly is a TZ file. (revanSZ)

3.0b1

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- Dropped Python 2 support
- Switched timezone provider from pytz to zoneinfo (PEP 615)

2.1

----------------

- No changes.

2.1b1

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- The is_dst flag is wrong for Europe/Dublin on some Unix releases.
I changed to another way of determining if DST is in effect or not.

- Added support for Python 3.7 and 3.8. Dropped 3.5 although it still works.

2.0.0

------------------

- No differences since 2.0.0b3

Links

• PyPI: https://pypi.org/project/tzlocal
• Changelog: https://pyup.io/changelogs/tzlocal/

[pyup-bot]

Closing this in favor of #440